duane allman's marshall

[JoeCon]

Could the switch near the tone controls be switcing the slope resistor? 56K for the DA and 33k for the HX??

[Roe]

anyway, it looks like a standard 1986 circuit.

[Mark]

Sorry to be a bit opinionated, but the Jimi Hendrix reference is plain wrong, as Paul Reed Smith's demo proves. The amp can't and doesn't produce that minor third feeding back.

https://www.youtube.com/watch?v=hB752mXdE9g

PRS plays a G here claiming it's like JH. Jimi plays an F# quite cleanly and it is the Fuzz Face comes in with the A (minor third) to the F# and the song begins.

https://www.youtube.com/watch?v=vC7fL4JwoEs

Same again with this clip.

https://www.youtube.com/watch?v=dgJwqUB ... e=youtu.be

That isn't to say it is a bad amp, but I don't think Mr PRS is being all that truthful with us.

Sorry, but I'm just a bit over this guys hype, he gets all excited like he has just found an ancient gem from the past.

[M Fowler]

http://www.youtube.com/watch?v=hB752mXd ... CNMhKpgHp4

http://www.youtube.com/watch?v=ew4QroazpyA

http://www.youtube.com/watch?v=09XL7O_doSk

[67plexi]

I'm trying to be fair but I don't hear anything related to a real Marshall Plexi 1986 or 1987
It is possible that the tube's are substandard . I don't hear any of the lush 3D harmonic's
that a good Marshall delivers. I'm sure PRS will sell a truck load of them.

Best regards, Steve.

[xtian]

Steve, you expect to hear "3D harmonics" in a youtube video?

[M Fowler]

I'n not sure it sounds like HX or DA amps either just providing videos talking about the history of the PRS HX/DA and Sewell/PRS talking about building amps.

Most of the PRS amps sound pretty good. I've talked to Greg Koch about the amp he was using for a teaching program he presented locally, it sounded like a Dumble honky tone, sounded very good. I think it was the PRS H amp.

Mark

[Mark]

It does annoy me that PRS sells to guys who think if they have the amp, then they'll have the tone. That may well be the case with high gain amps but for a lot of amps it's the guy playing the guitar that matters.

In the mid eighties I lived in London, by chance I went to Chandler's music at Kew Gardens. On this occasion they were selling one of Peter Townsend's black Schecter Tele's, it certainly looked like it had taken a beating, so I didn't doubt that it belonged to P.T.
Here it the thing, the guitar weighted a ton and was nothing special, just another guitar, P.T. Did all the great stuff.

I don't doubt for a second Duane's Marshall is your bog standard plexi Marshall. Yet PRS will lovingly sell you amp given to us by the grace of God.

I'll let it go now.

[Richie]

I think good equipment can inspire ones playing.. but for example,almost any sport, you can have the best field, court, or sandlot, but its the players that make the game happen. without them, its and empty playing field.

[dcribbs1412]

I think good equipment can inspire ones playing.. but for example,almost any sport, you can have the best field, court, or sandlot, but its the players that make the game happen. without them, its and empty playing field.

+1 great analogy

D

[67plexi]

I believe this to be a real Jimmi Hendrix amp if you look at the preamp board.
The resistors are a mixture of Allen Bradley CC, Piher and Iskra carbon film.
Every solder joint on the preamp board has been messed with.
What was the stock configuration of the resistors on this 1966/67 JTM45/100 I don't have a clue.
But My guess is that the 33k Iskra was a 56k at one time. I have owned a few 1986 Super Bass Marshalls and this resistor was a 47k stock looking at the DA amp or 1986 Super Bass 50 watt.
What I know for sure is when you replace the 56k to a 33k it totally changes the amp sound.
When you crank it up to full volume is distorts well like a Fuzz Face.
It would be interesting to have a on/on/on switch 56k, 47k 33k.
I just built this Amp and when I changed the 56k to 33k it sounds great it made every control more
interactive. My guess on the resistor's on the real Hendrix JTM45/100 is that it was blueprinted
every resistor was within 1% value. Just a guess.

Steve.

[JoeCon]

Steve

Sounds like you need Miles' Variable Slope control. He puts a 50kL pot in series with the 33K slope resistor giving you a wide array of tones...
"If you use 33k+25kl it gets you sweep between JMP and JTM stock slope values, but the extension,with a 50kl, up to 83k gets you sparkling highs that take it into Fender territory. "

[67plexi]

Joe thanks for the information. I went 6V6 with this build and set bias due to crap voltages at the clubs
we play. I have a computer guard surge protector that will not turn on unless the voltage is ok.
What I find funny is I built the DA amp from Mega-Plx Dumble a few years ago.
I respect Miles and ROE for their Marshall knowledge.

Best regards, Steve.

[stretch2011]

So I have another question for you guys. I'd love to build a 1986 super bass. But I don't need 50 watts of volume through a non-master amp. I'd love to have it, just don't need it. That's just too much for what I do. If I bought the 18 watt marshalls transformers and used el84's instead of el34's what would I have to do to the circuit board? Could I essentially keep the 50watt super bass circuit board and pair different transformers and tubes? I havn't tried anything like this before so I'm going to have to ask for some help.

[stretch2011]

By the way everyone, this is good stuff. Thanks for all the information